Apparatus equipped with worm means for digging a ditch or the like

ABSTRACT

An apparatus for digging a ditch by means of worms and capable of being secured to a vehicle, which apparatus comprises a group of at least four closely situated cooperating worms each disposed in an essentially upright position. Each of these worms has worm threading, with two respective ones of said worms cooperating with one another to define a front pair of worms and the remaining two worms cooperating with one another to define a rear pair of worms. Each worm of the front pair is in tandem with respect to a given worm of the rear pair. There is also provided means for imparting rotational movement to the worms of both pairs from the inside towards the outside when viewed from the front of the apparatus with each of the respective two worms which are arranged in tandem having the same direction of rotation and with their threading engaging with one another.

United States Patent Mengis et al. 1 Feb. 29, 1972 [54] APPARATUS EQUIPPED WITH WORM 799,753 9/1905 OConnor ..37/82 MEANS FOR DIGGI NG A BITCH OR 2,048,710 7/1936 Ranney..... .37/82 X THE LIKE 3,203,188 8 1965 Evans ..6l/72.6 3,309,875 3/1967 Niederwemmer... ..61/72.6 X [72] Inventors: Raphael Mengis, Muhlehofstrasse 14, 3,332,249 7/ 1967- ldoine ..6l/72.6

6030 Ebikon; Hans Mngls, Kirtenhofstrasse 38, 6000 Luzern, both of Switzer- P ima y E miner-Robert E. Pulfrey land Assistant ExaminerClifford D. Crowder [22] Filed, Feb 2 1970 Att0rneyWerner W. Kleeman [21] Appl. No.: 7,689 [57] ABSTRACT An apparatus for digging a ditch by means of worms and capa- [30] Foreign Application Priority Data ble of being secured to a vehicle, which apparatus comprises a group of at least four closely situated cooperating worms each Feb. 27, 1969 Switzerland ..2924/69 disposed in an essentially upright position Each of these worms has worm threading, with two respective ones of said 3632932 worms cooperating with one another to define a front pair of [58] Fieid 61/72 worms and the remaining two worms cooperating with one /95 i 67 another to define a rear pair of worms. Each worm of the front pair is in tandem with respect to a given worm of the rear pair. There is also provided means for imparting rotational move- [56] Rem-cums cued -ment to the worms of both pairs from the inside towards the UNITED STATES PATENTS outside when viewed from the front of the apparatus with each of the respective two worms which are arranged in tandem 3,039,203 6/1 962 Oglesby et a] 299/86 X having the same direction of rotation and with their threading 51:22: 3,044,753 7/1962 6 Claims, 8 Drawing Figures Wilcox, Jr ..299/68 Patented Feb. 29, 1972 5 Sheets-Sheet l Patented Feb. 29, 1972 3,645,019

5 Sheets-Sheet 2 Patented Feb. 29, 197

5 Sheets-Sheet 5 Patented Feb. 29, 1972 3,645,019

5 Shets-Sheet 4 Patented Feb. 29, 1972 5 Sheets-Sheet 5 APPARATUS EQUIPPED WITH WORM MEANS FOR DIGGING A DITCII OR THE LIKE BACKGROUND OF THE INVENTION The present invention relates to an improved apparatus for digging a ditch or trench by means of screws or worms, which apparatus can be connected to a vehicle. The invention is further concerned with an improved method for the operation of the aforementioned apparatus.

As a general rule, in equipment of this known type there is provided a feed worm which is inclined with respect to the horizontal. The feed worm conveys the earth which has been loosened by it along the underside towards the top. Other devices of the prior art possess a vertical worm for the same purpose which upwardly feed the excavated material in a tube partially surrounding such worm. Such apparatuses are only suitable for digging out flat ditches or trenches; they have the tendency of laterally deviating.

Furthermore, an apparatus is known to the art in which there is employed an essentially vertical cutter member for loosening the earth, whereas a, bucket elevator arranged behind such cutter removes the loosened earth. This type of apparatus actually belongs to the class of equipment known as bucket dredges, wherein the cutter which is arranged in front of thebucket elevator only serves the function of preloosening the earth for the bucket elevator. When using a bucket elevator for removing the earth, there results a limitation of the accommodatability to the required ditch depth. Additionally, there is always associated with a bucket elevator the drawback that it requires considerable feed forces which are only inconsequentially reduced by the cutter arranged therebefore, since it also requires feed forces.

Additionally, an apparatus is known to the art in which, for the purpose of removing the excavated material along the walls of the ditch there is provided a respective worm, whereby between these worms there is arranged an expelling or displacing body member which feeds the earth from the center of the ditch to the worms. In order to clean the ditches such type apparatus is useful. However, it becomes extremely problematic when a new ditch or trench is to be dug out, because the displacing body member and other cutting tools which determine the profile or shape of the ditch are pressed into the-ground by virtue of the feed force, so that the earth separates and the material can be delivered by the displacing body member to both worms. Yet, deep ditches cannot be dug out in this manner if they do not have a very wide scrape or chopping blade.

SUMMARY OF THE INVENTION readily subject to breakdown, extremely reliable in operation, I

and relatively easy to use.

Thus, in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the inventive apparatus of the aforementioned type is characterized by the features that it is provided with at least two laterally neighboring worms having oppositely directed worm pitch and which are driven in opposite rotational directions, and further, which, when viewed in the feed direction, at their front side rotate from the inside towards the outside.

By virtue of the fact that both worms rotate at their front side from the inside towards the outside, there is produced the been dug out, with the result that they convey such both towards the rear as well as towards the top. The earth can be prevented from carrying out a further rearward movement by the provision of a shield which bears or is situated behind the worms, so that the earth is now moved towards the center under the action of the rear wonns which are rotating towards one another, where coming from both sides it meets and now slides upon the worm, so that it can be moved upwardly along the shield member. This operation is particularly advantag'eous with interengaging worm members.

According to a special embodiment of the invention, there are provided a number of pairs of worms, especially four worms, namely, two rear feed worms and two ditch worms disposed in front of such feed worms. All four worms rotate at their front side advantageously from the inside towards the outside, and wherein the ditch worms loosen the earth and bring such in the described manner towards the rear to the feed or conveying worms which, again .in the previously described manner, further feed the earth towards the rear to the shield and along such towards the top. Also, in this particular instance it'is especially advantageous if both the feed worms as well as the ditch or trench worms interengage and the ditch worms engage with a respective feed worm.

If it is desired to operate with relatively high rotational speed of the ditch worms upon the earth, then, advantageously the feed worms are permitted to rotate equally quick or slower, whereby then the rotational speed can be used in accordance with different pronounced worm pitches. If one worm rotates slower by a multiple than the other, then, it can accordingly possess more threads. The same also holds true when it is desired to rotate the ditch worms with relatively higher contact pressure slower, whereas for increasing the slip of the earth upon the feed or conveying worms and, therefore, for increasing the vertical feed capacity, the feed worms can be permitted to rotate quicker. The rotational speed of the worms can thus, accordingly, be indirectly proportional to their number of threads.

The ditch'worms can be provided with teeth at least along their outside edge, or they can be spaced from the worm shaft and exhibit teeth arranged along at least a helical line. Also, a combination of both types of tooth arrangement is possible with multiple thread worms, especially if the worm in question should serve both as a ditch worm as well as also as a feed or conveying worm.

Concerning the shield member, such can possess forwardly directed edges which can be provided both at the sides as well as at the bottom, whereby also surfaces can be provided which wipe along the walls and the floor of the dug out ditch or trench. 1

These surfaces can be extended towards the rear so that, to a certain extent, they form a sliding shell. This is then of particular advantage when the ditch or trench should contain a filler or filling material directly after the digging out operation. It is indeed possible with an inventive apparatus to fill a dug out ditch with a supporting liquid, for instance, Bentonite in ground which is not very sturdy and, then, in known manner, thereafter to fill in the final filler material, or to brace the ditch and thereafter to fill same. The invention furthermore additionally offers also the possibility of proceeding in a different way. Accordingly, the invention further relates to a method for operating the inventive apparatus for the simultaneous digging out and filling of a ditch or trench which is characterized by the feature that directly after the digging out of the ditch while presenting the utilization of an intermediate support arrangement for the ditch walls there is introduced the final filling material into the ditch. In so doing, it is advantageous-if the inventive apparatus supports an infeed pipe or conduit for the tiller or filling material. If conduits are to be laid, then, an apparatuscan be used which directly brings the.

For instance, during the formation of concrete walls in the ground the inventive method is of particular advantage. It can also then be of advantage if it is desired to use the ditch for other purposes, for instance, to produce a seal of clay or other material, for the introduction of seepage or drainage material, such as gravel and sand, or for the laying of conduits or pipes. By providing suitable stratification it is possible to also introduce a number of fillers in superimposed fashion or next to one another.

Depending upon their usefulness, the worms can be arranged more or less inclined in the lengthwise direction of the ditch or trench, whereby, however, an arrangement of the worms which is as vertical as possible is preferred because it is possible to carry out excavation, also between obstacles, for instance neighboring buildings, where the ditches end at such obstacles or almost come close to the obstacle, and further, to produce curved or bent ditches.

In order to laterally dispose of the excavated material, it is possible to allow such, for instance, to slide upon a suitable chute or slide arrangement. Yet, if the ditchand feed worms should penetrate as deep as possible into the ground, then, advantageously a lateral conveyor or feed member can be placed at the upper end of the feed worm which laterally conveys away the material which is brought to the top and, thereby, eventually further raises same, for instance for directly loading the excavated material. For this purpose, a feed worm which moves in a housing has been found to be suitable, because the excavated material brought to the top can be directly laterally fed into its one end.

The ditch and/or feed worms are advantageously drivingly connected so that the relationship of their rotational speed automatically can be maintained mutually constant in accordance with their pitch angle, even if the rotational speed changes for some reason.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood, and objects other than those set forth above, will become apparent, when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:

FIG. 1 is a side view of anembodiment of inventive ap-- paratus equipped with four interengaging worms, whereby the shield member has been partially cut away;

FIG. 2 is a front view of the apparatus structure shown in FIG. I and viewed in the direction of the arrow II, whereby the upper portion of the worms and a portion of the drive have been broken away;

FIG. 3 is an enlarged fragmentary portion or section of the region III shown in FIG. 1, without the shield member and the background;

FIG. 4 is a sectional view taken along the line IVIV of FIG. 1;

FIG. 5 is a fragmentary view from the front of an inventive apparatus equipped with only two worm members;

FIG. 6 is a sectional view taken along the line VIVI of FIG. 5; FIG. 7 is a schematic illustration of the drive arrangement of the apparatus structure depicted in FIGS. 14; and

FIG. 8 is an illustration of an apparatus corresponding to that of FIG. 4 and equipped with a delivery or infeed conduit visible at the shield member for the material which is to be brought into the ditch or trench.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Describing now the drawings, initially reference will be made to the apparatus structure depicted in FIGS. 1-4, inclusive, to the drive arrangement thereof as shown in FIG. 7 and to its special constructional form as depicted in FIG. 8. Referring now to FIG. 1, more specifically, there will be recognized a caterpillar vehicle T possessing an hydraulic lifting device, which is generally designated by reference character H, and for the purpose of improving the comprehensibility of the important aspects of the invention has been conveniently omitted in FIG. 2 in order to also improve the illustration of the drawings. This is especially so because hydraulic lifting devices I-I suitable for purposes of the present invention are well known to the art and the particular aspects of the invention are not specifically directed thereto. The vehicle T travels, as best shown in FIG. 2, adjacent the ditch or trench G, the bottom or floor GB of which can best been seen in FIGS. 1 and 2, and its side walls GS in FIGS. 2, 4 and 8. But, it is to be understood that this vehicle T could also travel over or in the ditch, if such were desirable.

While in FIG. 1 the front ditch wall has been omitted in order to improve the illustration, it has been shown in FIGS. 4 and 8 by reference characters GV. By referring to these figures, it will be recognized that the ditch or trench worms 1 and 1' which possess opposed worm pitch work the front wall GV of the ditch or trench in the direction of the indicated arrows. The ditch worms 1 and I possess at each respective worm shaft 2 and 2', radially protruding teeth 3 and 3' defining respective worm threading, respectively, as such have been shown in FIGS. 1 and 2, but with greater clarity in FIG. 3. These radially protruding teeth 3 and 3' are arranged along three helical or screw lines, that is to say that the ditch worms are three-threaded. As will be particularly evident by referring to FIGS. 4 and 8, the ditch worms 1 and 1' engage or mesh with one another by means of their teeth 3 and 3', respectively. Arranged behind the ditch worm l is the feed or conveying worm 4 and arranged behind the ditch worm 1' there is the feed or conveying worm 4'. The feed or conveying worms 4 and 4 each possess an uninterrupted single thread worm 5 and 5', respectively, at the associated worm shafts 6 and 6' respectively, whereby they rotate in the direction of the indicated arrows of FIGS. 4 and 8.

During the digging operation, the inventive apparatus moves in the direction of the arrow 7 indicated in FIG. 4. A shield member 8, or equivalent structure, is mounted behind the feed or conveying worms 4 and 4', which shield member is provided at its central region with a guide body member 8', and furthermore, at its side is equipped with the surface members for smoothing the ditch or trench. Furthermore, the surface members 8" of the shield member 8 form knife edges 9 together with the parts of the shield member 8 which are angled at an incline towards the front and extend transverse to the ditch, as best shown in .FIG. 4 for instance. In FIG. 8, the guide body member 8 has been omitted in favor of a conduit which will be described in greater detail hereinafter.

The synchronous movement of the worm members I, 1, 4, 4' is effectuated by virtue of the drive arrangement depicted in FIG. 7. Large gears Z1, 21 are arranged upon the worm shafts 2 and 2, respectively, whereas upon the worm shafts 6 and 6 there are located smaller gears Z2 and Z2 respectively. The gears Z1, and Z1 mesh with one another and each with one of the gears Z3, Z3, which are disposed upon both motor shafts MW, MW of the motors M, M (FIGS. 1 and 2). The gears Z3, Z3 engage or mesh with the respective gears Z2,

' 22'. Accordingly, it is possible to use two drive motors and by virtue of the meshing of the gears Z1, Z1 to nonetheless insure for an absolute synchronous running, One can easily recognize that by virtue of the different transmission ratio of the gears Z3 and Z3 with respect to Z1 or Z2 and Z1 or Z2, respectively, it is possible to obtain a rotational speed of the worms 1, 1', on the one hand and, the worms 4, 4', on the other hand, in a relationship which is indirectly proportional to their thread number and is a function of their pitch. Thus, the worms 1, I can move slower and, therefore, act with more force, whereas the worms 4, 4' rotate quickly and thus bring about an increased slip of the material which, in turn, corresponds to an increased vertical feed capacity, whereby there can be prevented that the earth which has been loosened and brought towards the rear by the worms 1, 1 will cause any clogging of the worms 4, 4.

The arrangement depicted in FIGS. 5 and 6 functions similar to that of FIGS. 3 and 4, whereby, here however, the feed or conveyor worms 40 and 40' with their worm shafts 60,

60', respectively, and the worm threads 50, 50', respectively, with opposite pitch and opposite direction of rotation, according to the arrows shown in FIG. 6, simultaneously serve as ditch and also conveying worm means. The shield member 8 corresponds completely to the shield member previously described and illustrated in FIGS. 4 and 8. In accordance with the combined utilization of this equipment for digging and conveying, the worms 40 and 40' could either be provided with teeth at the threads 50 and 50', respectively, or along additional threads could have teeth corresponding to the teeth 3 and 3' of the worms 1 and 1', respectively, of the arrangement shown in FIGS. 3 and 4.

The mode of operation has already been described heretofore so that it is only necessary to briefly mention that the worms 1, l, 4, 4', 40, 40' which rotate at the ditch walls GS from the front towards the rear bring about a feed action in the direction of the arrow 7 of FIG. 4.

The shafts 2, 2', 6, 6', 60 and 60 can be hollow, so that they can be conveniently used for the introduction of any type of desired material, for instance a pipe or conduit into the ditch or trench.

As best observed by referring to FIGS. 1 and 2, a worm or screw member 101 is accommodated in a housing 100, this worm member 101 possessing the function of laterally conveying away the excavated material which is brought to the top by the conveying worms 4 and 4', so that the material can be directly loaded and transported away. In place of the worm 101 there could naturally also be used a completely different type of conveying element, forinstance a conveyor band, or any other type of equivalent or suitable structure.

ln the case of particularly long worm members, it is advantageous to provide intermediate support means, for instance at the shield member. In FIG. 1 there is shown a support L at the lower end of the shield member 8. Furthermore, in the neighborhood of the support member L there is provided a cutting edge 9' which is similar to one of the edges 9 of the previously described shield member 8, and from which cutting edge 9' there extends along the floor or bottom GB of the ditch a surface portion 9" to the rear side of the shield member. The reason or function for this surface member 9" is, on the one hand, to guide the edge 9' and, on the other hand, serves to smooth the ditch floor GB. In addition to the previously given explanation in respect of FIG. 4 concerning the shield member 8 and the worms 1, l, 4, 4', by now referring to FIG. 8 there should be mentioned that at the rear side of the shield member 8 there is located an infeed conduit or pipe 80 through which filling or filler material can be introduced into the ditch G. For this purpose the conduit or pipe 80 possesses a wide slot 81 at its rear side, which by means of a likewise slotted inner pipe or tube 82, which is rotatable in the outer pipe 80, can serve to close the slot 81. Hence, it is possible by virtue of the rotational position of the pipe or conduit 82 with respect to the pipe or conduit 80 to control the quantity of filler material which is to be introduced into the ditch G.

tion, that the objects set forth at the outset to the specification have been successfully achieved. Accordingly,

What is claimed is:

' 1. An apparatus for digging a ditch by means of worms, such apparatus being capable of being secured to a vehicle, comprising a group of at least four closely situated cooperating worms each disposed in an essentially upright position, each of said worms having means defining wonn threading, two

respective ones of said worms cooperating with one another to define a frontfilair of worms and the remaining two worms cooperating WI one another to define a rear pair of worms,

and each worm of the front pair being in tandem with respect to a given worm of the rear pair, means for imparting rotational movement to the worms of both pairs from the inside towards the outside when viewed from the front of the apparatus with each of the respective two worms which are arranged in tandem having the same direction of rotation and with their threading engaging with one another.

2. The apparatus as defined in claim 1, wherein each worm engages by means of its threading into the threading of the neighboring worms, and wherein both worms of the front pair of wonns have the same magnitude of their threading pitch but opposite pitch sense, and wherein both of the rear pair of worms have the same magnitude of their threading pitch but opposite pitch sense.

3. The apparatus as defined in claim 2, wherein each worm engages with its threading into the threading of at least two neighboring worms.

4. The apparatus as defined in claim2, wherein said rotational movement imparting means incorporates gearing means for operatively connecting the four worms with one another such that the rotational speed of the two worms of the rear pair of worms is a multiple of the rotational speed of the two worms of the front pair of worms and the pitch of the front pair of worms is steeper than the pitch of the rear pair of worms.

5. The apparatus as defined in claim 4, wherein the front pair of worms possess fewer threading that the rear paid of worms as a function of the relationship of the rotational speeds of the front and rear pairs of worms with respect to one another.

6. The apparatus as defined in claim 1, wherein the threading of the front pair of worms embodies teeth means at its periphery. 

1. An apparatus for digging a ditch by means of worms, such apparatus being capable of being secured to a vehicle, comprising a group of at least four closely situated cooperating worms each disposed in an essentially upright position, each of said worms having means defining worm threading, two respective ones of said worms cooperating with one another to define a front pair of worms and the remaining two worms cooperating with one another to define a rear pair of worms, and each worm of the front pair being in tandem with respect to a given worm of the rear pair, means for imparting rotational movement to the worms of both pairs from the inside towards the outside when viewed from the front of the apparatus with each of the respective two worms which are arranged in tandem having the same direction of rotation and with their threading engaging with one another.
 2. The apparatus as defined in claim 1, wherein each worm engages by means of its threading into the threading of the neighboring worms, and wherein both worms of the front pair of worms have the same magnitude of their threading pitch but opposite pitch sense, and wherein both of the rear pair of worms have the same magnitude of their threading pitch but opposite pitch sense.
 3. The apparatus as defined in claim 2, wherein each worm engages with its threading into the threading of at least two neighboring worms.
 4. The apparatus as defined in claim 2, wherein said rotational movement imparting means incorporates gearing means for operatiVely connecting the four worms with one another such that the rotational speed of the two worms of the rear pair of worms is a multiple of the rotational speed of the two worms of the front pair of worms and the pitch of the front pair of worms is steeper than the pitch of the rear pair of worms.
 5. The apparatus as defined in claim 4, wherein the front pair of worms possess fewer threading that the rear paid of worms as a function of the relationship of the rotational speeds of the front and rear pairs of worms with respect to one another.
 6. The apparatus as defined in claim 1, wherein the threading of the front pair of worms embodies teeth means at its periphery. 